CPR techniques are for use in reviving persons whose breathing and heartbeat have stopped. CPR must be done immediately, by whoever is at hand, if it is to be effective. There is no time to wait until medical practitioners arrive.
Persons who know this and are concerned about being prepared for emergencies therefore wish to learn how to do CPR. This is especially so if the person has, for example, a relative who is likely to suffer a cardio-pulmonary arrest.
The knowledge that the patient will die if the CPR is done badly induces panic. Only those actions which have been so thoroughly drilled and practiced that they are automatic can be relied on in the heat and stress of such a moment.
People recognize this, and accordingly, there are many courses on CPR, widely available to the public.
In CPR, the rescuer carries out a series of compressions of the patient's chest. These are for the purpose of squeezing the heart, firstly to stimulate the heart's pumping action, to keep the blood circulating; and secondly to induce the heart to resume its own pumping action. The rescuer also carries out mouth-to-mouth respiration, again for the dual purposes of keeping up a supply of air to the patient, and of inducing the patient's lungs to resume their own action.
In the CPR courses, the instructor helps the students with practising the necessary movements, either on real people or on dummies. A whole industry has arisen for supplying these dummies, the concern being in each case to make the dummy more and more like a real patient.
The following patents may be regarded as showing the state of the art of such dummies:
U.S. Pat. No. 3,049,811 (Ruben, Aug. 21, 1962) PA0 U.S. Pat. No. 3,199,225 (Robertson, Aug. 10, 1965) PA0 U.S. Pat. No. 3,276,147 (Padellford, Oct. 4, 1966) PA0 U.S. Pat. No. 3,994,075 (Kohnke, Nov. 30, 1976) PA0 U.S. Pat. No. 4,001,950 (Blumensaadt, Jan. 11, 1977) PA0 G.B. Pat. No. 791,741 (Latham, Mar. 12, 1958)
It is recognized in the present invention that the student has two different kinds of skill to learn if he or she is to master CPR. The first kind of skill lies in becoming aware of what is feels like to breath air into someone else's lungs, or to massage someone else's heart, and in learning how hard to press and to blow.
In this first kind of skill should be included the skill that results in learning just exactly where to press a persons s chest, and with what part of the hand, to avoid the chance of injuring the patients ribs and organs.
The second kind of skill, for the purposes of the invention, lies in acquiring knowledge of how many times to repeat the chest compressions, and at what rate, and in learning when to interpose spells of respiration, and again at what rate.
One may characterize the first kind of skill as learning what it feels like to carry out CPR. One may characterize the second kind of skill as the purely mental skill of remembering sequences of actions, time intervals, and rates.
The present invention provides an aid for practising the second kind of skill. Since the aid of the invention is not intended to simulate what CPR feels like, the aid can be extremely low-priced. The dummies previously referred to are far too expensive for the ordinary CPR student to own. The dummies are made for sale to the course organizers, not to the students.
A student's skill in CPR tends to fall to a practically useless level unless the student attends periodic refresher courses, say once a year. It is recognized in the present invention, that the thing that the student tends to forget is the second, mental memory, kind of skill. The student does not tend to forget what CPR feels like. Therefore, a practise aid which only allows the mental, memory, aspects to be practiced, and not the physical aspects, is virtually just as useful to practice on as a regular highly expensive dummy.
Naturally, the student does have to attend a course, and to be started off on a dummy; but once the student has learned what CPR feels like, the student tends not to forget that aspect, or at least the student tends not to forget that aspect quite so quickly as he forgets the memory aspects.
It is an aim of the present invention to provide a teaching and practice aid which is of such a construction that is just sufficiently like a dummy as to make the CPR action meaningful when performed on it, but is otherwise as simple and inexpensive as possible.
It is a further aim of the present invention to provide a practise aid that is inexpensive enough to be purchased by any student, preferably when the student is attending a CPR course. The aid may then be taken home by the student for practice at the student's own convenience.
It is to be noted with respect to the apparatus of the patents mentioned above, that keeping the dummies clean and hygienic is a major problem for the course organizers. There is no hygiene problem with the aid of this invention, since each aid is intended for use by only one student.
There have been practice aids proposed previously, which have been less expensive regular dummies. In U.S. Pat. No. 3,152,404 (CHESHIRE, Oct. 13, 1964) for example, a device is shown which fits over the mouth and chest of a real person. This device is intended to avoid the problem that mouth-to-mouth resuscitation with a person who is breathing normally is quite unlike that with a person who has stopped breathing.
In U.S. Pat. No. 4,095,590 (HARRIGAN, June 20, 1978) the device is not intended to be like a dummy, but the device includes (expensive) means for indicating to the student when he is pressing too hard. It is a vital part of CPR training for the student to learn how hard to press, but that is a part of the training that is not intended to be covered by the aid of the present invention.
The aid itself, in this invention, includes a solid stand, which has a base for resting on the floor. A horizontal platform is positioned above the base on a pillar or pedestal, so that the platform is roughly at the height of a person's chest, when the person is lying face up on the floor.
A pad of foam material rests on the platform. Pressing down on such a pad feels quite markedly unlike pressing down on someone's chest; but that is of little importance, as has been explained.
Attached to the stand is a length of tubing, one end of which is open, and which is so positioned as to simulate the mouth of a person lying face up on the floor. The tubing is so made that it supports itself, once set, in the mouth-simulating position. At the other end of the tube is a simple balloon; and blowing into the tube is effective to inflate the balloon.
Again, blowing into the tube feels quite markedly different from blowing into a person's mouth; but again that is of little importance, as has been explained.